biostudies-literatureWelters CDeutsche ForschungsgemeinschaftEuropean Research CouncilDeutschen Konsortium für Translationale KrebsforschungEuropean Union ERC Advanced GrantDeutsche KrebshilfeBerliner Krebsgesellschaft e.V.1407-1419https://www.ebi.ac.uk/biostudies/studies/S-EPMC9627264biostudies-literatureUnknown10(11)Multiple myeloma is a hematologic malignancy of monoclonal plasma cells that accumulate in the bone marrow. Despite their clinical and pathophysiologic relevance, the roles of bone marrow-infiltrating T cells in treatment-naïve patients are incompletely understood. We investigated whether clonally expanded T cells (i) were detectable in multiple myeloma bone marrow, (ii) showed characteristic immune phenotypes, and (iii) whether dominant clones recognized antigens selectively presented on multiple myeloma cells. Single-cell index sorting and T-cell receptor (TCR) αβ sequencing of bone marrow T cells from 13 treatment-naïve patients showed dominant clonal expansion within CD8+ cytolytic effector compartments, and only a minority of expanded T-cell clones expressed the classic immune-checkpoCancer immunology researchImmune Phenotypes and Target Antigens of Clonally Expanded Bone Marrow T Cells in Treatment-Naive Multiple Myeloma.PMC9627264390857198882963PE 3127/1-1HAFF202013 MM70113355Blanc ERahn HPWelters CDornmair KMoosmann AStrobel JBullinger LHackstein HPenter LHansmann LGerbitz ABeule DBuccitelli CDietze KHsu MTPopp OBen Hamza AChen XMertins PBlankenstein TStein CALammoglia Cobo MFfalseImmune Phenotypes and Target Antigens of Clonally Expanded Bone Marrow T Cells in Treatment-Naive Multiple Myeloma.Multiple myeloma is a hematologic malignancy of monoclonal plasma cells that accumulate in the bone marrow. Despite their clinical and pathophysiologic relevance, the roles of bone marrow-infiltrating T cells in treatment-naïve patients are incompletely understood. We investigated whether clonally expanded T cells (i) were detectable in multiple myeloma bone marrow, (ii) showed characteristic immune phenotypes, and (iii) whether dominant clones recognized antigens selectively presented on multiple myeloma cells. Single-cell index sorting and T-cell receptor (TCR) αβ sequencing of bone marrow T cells from 13 treatment-naïve patients showed dominant clonal expansion within CD8+ cytolytic effector compartments, and only a minority of expanded T-cell clones expressed the classic immune-checkpo2022-01-01T00:00:00Z2022 Nov2026-05-28T03:42:58.267Z2025-04-04T20:22:18.924ZS-EPMC96272643612241010.1158/2326-6066.CIR-22-0434